This invention relates to a vehicle towing trailer of such a type as is trailed by a pulling vehicle to which a front end of the trailer is detachably connected by means of a hitching device.
The conventional vehicle towing trailer of the above type generally has a pair of ground engaging wheels non-removably mounted to the underside of the trailer end portion and also has a wheel supporting frame mounted on the rear body of the trailer so as to swivel in a horizontal plane and slide back and forth in the axial direction for the convenience of placing the front or the rear wheels of a vehicle to be towed thereon. In operation, the vehicle wheels are placed on the slid-down wheel supporting frame, and then the wheel supporting frame together with the vehicle wheels supported thereon is slidably pulled up by means of a winch provided on the trailer body. Thus, the conventional trailer of this type has the following disadvantages, the first being that the non-removability of the ground engaging wheels from the trailer body invites a considerably great height or distance from the ground surface to a level where the wheel supporting frame lies, thereby to cause an obstacle to a quick and simple placing of the wheels of the vehicle to be towed onto the wheel supporting frame; the second being that the aforesaid considerably great height or distance inevitably invites a considerably great axial length of the trailer body in the viewpoint of preventing an excessively steep angle of the slideway for the wheel supporting frame; and the third being that the inevitable large dimension of the trailer body generally invites high costs in manufacture, transportation, storage and maintenance as well as inconvenience in use.
In order to eliminate the above-discussed disadvantages, the inventor of the present invention previously proposed an improved vehicle towing trailer as disclosed in Japaness Utility Model Publication No. 56-17224 published on Apr. 22, 1981 (application No. 54-14119), in which a pair of spaced ground engaging wheel assemblies are removably mounted to the underside of the trailer end portion, and the trailer body is so constructed as to be raised and lowered by means of a jack mounted thereon. Thus, in order to place the wheels of a vehicle to be towed onto a pair of wheel supporting frames, the rear end of the trailer is lowered after the ground engaging wheel assemblies have been removed from the trailer body. After the wheels of the vehicle to be towed have been seated on the wheel supporting frames, the rear end of the trailer is raised up by means of the jack so that the removed ground engaging wheel assembly can be re-mounted to the trailer body. After the ground engaging wheel assemblies have been re-mounted, the jack is withdrawn into its resting position so that the trailer body is slightly lowered until the ground engaging wheels are supported on the ground. The removability of the ground engaging wheel assemblies from the trailer body enables the rear end of the trailer body to be lowered down toward the ground surface and permits an easy placing of the wheels of the vehicle to be towed onto the pair of wheel supporting frames with the aid of a gentle slope of a ramp plate. Further, dimension of the trailer body can be minimized, and the winch and the slidable construction of the wheel supporting frame are no longer required.
However, the trailer as disclosed in Japanese Utility Model Publication No. 56-17224 is so constructed that the re-mounting of the pair of ground engaging wheel assemblies must be carried out by inserting a mounting shaft extending upwardly from a wheel supporting bracket, which supports a ground engaging wheel, into each of a pair of spaced tubular sockets extending downwardly from the underside of either end of the rear frame which extends transversely of the longitudinal axis of the trailer body. In order to carry out attachment or re-mounting of the ground engaging wheel assembly, an operator must bend himself down at a position very close to one side of the rear frame of the trailer. As described above, the re-mounting of the ground engaging wheel assembly to the trailer body is carried out with the wheels of the vehicle to be towed placed on the wheel supporting frames while the jack is in its operative position to maintain the rear end of the trailer body in its raised position. Thus, if the jack at this stage suddenly loses its balance or becomes inoperative unexpectedly by a certain reason or other, the operator may be caught under the falling trailer body or the vehicle supported on the same. Therefore, the trailer of this prior art is occasionally dangerous in practical use.
It is an object of the present invention to eliminate the disadvantages in the above-described vehicle towing trailer as disclosed in Japanese Utility Model Publication No. 56-17224.
Another object of the invention is to provide an improved vehicle towing trailer which is safe, simple, convenient and easy to use.
A further object of the invention is to provide an improved vehicle towing trailer which permits a minimized dimension and manufacture at a low cost.
One feature of the present invention is that the re-mounting of a pair of detachable ground engaging wheel assemblies to the trailer body can be carried out by an operator who stands in a safety zone near one side of a rear frame of the trailer body. In order to realize this feature, the trailer according to the invention has a substantially T-shaped body comprising an elongated tubular frame extending in parallel with a longitudinal axis of the trailer body, and a cross frame connected to the rear end of the elongated frame and extending transversely of the same, so that the re-mounting of each of a pair of wheel assemblies can be carried out by an operator who stands aside the elongated tubular frame at a position between the cross frame and a rear end of a pulling vehicle to which the front end of the elongated frame is detachably connected. At this position, the operator can easily get out of danger of being caught under the falling trailer body or the vehicle placed on the wheel supporting frames of the trailer.
Another feature of the invention is that the re-mounting of the wheel assembly can be performed in a quick and simple manner by merely inserting male members formed with a wheel supporting bracket into female members formed with the cross frame, from the front side toward the rear side of the cross frame, viz. in an axial direction opposite to a running direction of the trailer. This feature also enhances safety in the re-mounting of the wheel assembly to the trailer body and prevents unexpected disengagement of the male members out of the female members when the trailer is running.
A further feature of the invention is that, in order to meet a necessity in such a particular case where a vehicle to be towed is so greatly damaged that neither the front wheels nor the rear wheels thereof can be seated on a pair of wheel supporing frames, a certain body portion of the vehicle to be towed can be directly supported on a supporting platform of the trailer. In order to realize this feature, the supporting platform is arranged so as to turn horizontally about a vertical axis while the pair of wheel supporting frames are pivotally and detachably mounted to the platform at opposite ends thereof for the convenience of placing the greatly damaged vehicle body directly thereon.
A still further feature of the invention is that the trailer is applicable to various height or distance from a ground surface to a level where a hitching member fixed to a pulling vehicle lies. In order to realize this feature, each of the pair of wheel supporting frames is arranged so as to be pivotally movable about a horizontal axis, so that, when the trailer end is lowered for placing the wheels of the vehicle to be towed onto the wheel supporting frames, an inclination angle of each of the wheel supporting frames with respect to the ground surface is not so steep regardless of a value of the aforesaid height or distance.
A still further feature of the invention is that, in particular embodiments as illustrated in FIGS. 10 and 11, it is no longer necessary to pull up the vehicle to be towed until its wheels can be seated in the pair of wheel supporting frames. In order to realize this feature, each of the pair of wheel supporting frames has a detachable cross bar selectively engageable with a pair of a plural number of supporting holes or slots formed in each of a pair of side plates constituting the wheel supporting frame. The cross bar is removed from the wheel supporting frame before a wheel of the vehicle to be towed is inserted into position between the pair of side plates. After the wheel is properly interposed, the cross bar is mounted to the pair of side plates by engaging the same with a selected one pair among a plurality of opposed pairs of the supporting holes or slots, Thus, the wheel of the vehicle to be towed can be seated by its own weight into the wheel supporting frame as the rear end of the trailer is raised by means of a jack or lift arm mounted on the trailer body. This feature also enhances applicability to several dimensions of the wheel of the vehicle to be towed.
Other objects, features and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become obvious to those skilled in the art from this detailed description.